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6ce14f6416
We copy a local resource structure into a list, but only
initialize some of its members, as pointed out by gcc-4.4:
drivers/acpi/acpi_watchdog.c: In function 'acpi_watchdog_init':
drivers/acpi/acpi_watchdog.c:105: error: 'res.child' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.sibling' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.parent' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.desc' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.name' may be used uninitialized in this function
Newer compilers can presumably optimize the uninitialized access
away entirely and don't warn at all, but rely on the kzalloc()
to zero the structure first. This adds an explicit initialization
to force consistent behavior.
Fixes: 058dfc7670 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
129 lines
3.2 KiB
C
129 lines
3.2 KiB
C
/*
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* ACPI watchdog table parsing support.
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*
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* Copyright (C) 2016, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) "ACPI: watchdog: " fmt
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#include <linux/acpi.h>
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#include <linux/ioport.h>
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#include <linux/platform_device.h>
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#include "internal.h"
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/**
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* Returns true if this system should prefer ACPI based watchdog instead of
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* the native one (which are typically the same hardware).
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*/
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bool acpi_has_watchdog(void)
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{
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struct acpi_table_header hdr;
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if (acpi_disabled)
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return false;
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return ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_WDAT, 0, &hdr));
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}
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EXPORT_SYMBOL_GPL(acpi_has_watchdog);
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void __init acpi_watchdog_init(void)
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{
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const struct acpi_wdat_entry *entries;
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const struct acpi_table_wdat *wdat;
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struct list_head resource_list;
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struct resource_entry *rentry;
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struct platform_device *pdev;
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struct resource *resources;
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size_t nresources = 0;
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acpi_status status;
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int i;
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status = acpi_get_table(ACPI_SIG_WDAT, 0,
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(struct acpi_table_header **)&wdat);
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if (ACPI_FAILURE(status)) {
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/* It is fine if there is no WDAT */
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return;
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}
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/* Watchdog disabled by BIOS */
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if (!(wdat->flags & ACPI_WDAT_ENABLED))
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return;
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/* Skip legacy PCI WDT devices */
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if (wdat->pci_segment != 0xff || wdat->pci_bus != 0xff ||
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wdat->pci_device != 0xff || wdat->pci_function != 0xff)
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return;
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INIT_LIST_HEAD(&resource_list);
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entries = (struct acpi_wdat_entry *)(wdat + 1);
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for (i = 0; i < wdat->entries; i++) {
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const struct acpi_generic_address *gas;
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struct resource_entry *rentry;
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struct resource res = {};
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bool found;
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gas = &entries[i].register_region;
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res.start = gas->address;
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if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
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res.flags = IORESOURCE_MEM;
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res.end = res.start + ALIGN(gas->access_width, 4);
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} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
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res.flags = IORESOURCE_IO;
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res.end = res.start + gas->access_width;
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} else {
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pr_warn("Unsupported address space: %u\n",
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gas->space_id);
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goto fail_free_resource_list;
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}
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found = false;
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resource_list_for_each_entry(rentry, &resource_list) {
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if (rentry->res->flags == res.flags &&
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resource_overlaps(rentry->res, &res)) {
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if (res.start < rentry->res->start)
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rentry->res->start = res.start;
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if (res.end > rentry->res->end)
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rentry->res->end = res.end;
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found = true;
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break;
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}
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}
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if (!found) {
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rentry = resource_list_create_entry(NULL, 0);
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if (!rentry)
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goto fail_free_resource_list;
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*rentry->res = res;
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resource_list_add_tail(rentry, &resource_list);
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nresources++;
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}
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}
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resources = kcalloc(nresources, sizeof(*resources), GFP_KERNEL);
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if (!resources)
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goto fail_free_resource_list;
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i = 0;
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resource_list_for_each_entry(rentry, &resource_list)
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resources[i++] = *rentry->res;
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pdev = platform_device_register_simple("wdat_wdt", PLATFORM_DEVID_NONE,
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resources, nresources);
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if (IS_ERR(pdev))
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pr_err("Device creation failed: %ld\n", PTR_ERR(pdev));
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kfree(resources);
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fail_free_resource_list:
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resource_list_free(&resource_list);
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}
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